Solid state lighting fixtures

ABSTRACT

The present disclosure provides a solid state lighting fixture that can be used in outdoor and indoor recessed lighting applications. The solid state lighting fixture has a recessed housing configured to be installed in a recess, and a solid state light assembly capable of being secured to the housing outside the recess. The solid state light assembly is at least partially made of a heat dissipating material capable transferring heat generated by the solid state light assembly to ambient air.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to co-pending U.S. ProvisionalApplication No. 62/155,264, filed on Apr. 30, 2015, titled “FlexibleHousing Assembly for SSL Light Fixtures,” co-pending U.S. ProvisionalApplication No. 62/155,166, filed on Apr. 30, 2015, titled “Solid StateLight Fixtures with Integrated Controls,” co-pending U.S. ProvisionalApplication No. 62/155,293, filed on Apr. 30, 2015, titled “ControlDevice for Solid State Light Fixtures,” and co-pending U.S. ProvisionalApplication No. 62/156,251, filed on May 2, 2015, titled “Solid StateLighting Fixtures,” all of which are hereby incorporated herein byreference in their entireties.

BACKGROUND

1. Field

The present disclosure relates generally to the field of lightingfixtures, and more particularly, the present disclosure relates torecessed solid state lighting fixtures.

2. Description of the Related Art

Recent advances in solid-state lighting technologies, particularly inlight emitting diode (LED) lighting technologies, offer significantlylonger operational lifetimes and increase lighting efficiencies whichenable significant energy and cost savings. These benefits providemotivation to use solid-state lighting technologies in a number ofdifferent applications, including recessed lighting applications. Adifficulty with recessed solid state lighting fixtures is thedissipation of heat generated by the solid state lighting elements.

SUMMARY

The present disclosure provides a solid state lighting (SSL) fixturethat can be used in outdoor and indoor recessed lighting applications.In an exemplary embodiment, the SSL fixture includes a recessed housingconfigured to be installed in a recess, and an SSL assembly capable ofbeing secured to the housing outside the recess. The SSL assembly ismade of a heat dissipating material capable transferring heat generatedby the SSL assembly to ambient air.

The present disclosure also provides SSL assemblies that have an SSLlight engine and a housing capable of dissipating heat generated by theSSL light engine. In an exemplary embodiment, the SSL assembly includesan external housing and an SSL light engine secured within a recesswithin the external housing. The SSL light engine includes one or moreSSL light elements mounted to a light engine board. The external housingis made of a heat dissipating material capable transferring heatgenerated by the SSL light engine to ambient air.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures depict embodiments for purposes of illustration only. Oneskilled in the art will readily recognize from the following descriptionthat alternative embodiments of the structures illustrated herein may beemployed without departing from the principles described herein,wherein:

FIG. 1 is a side view of a recessed SSL fixture according to someembodiments of the present disclosure;

FIG. 2 is another side view of a recessed SSL fixture of FIG. 1;

FIG. 3 is a top plan view of the recessed SSL fixture of FIG. 1;

FIG. 4 is an image of a recessed SSL fixture from the side illustratinga space between a recessed housing and an SSL assembly;

FIG. 5 is an exploded perspective view of the SSL fixture of FIG. 1,with parts of the SSL fixture shown separated;

FIG. 6 is a parts list for the recessed SSL fixture of FIG. 5;

FIG. 7 is an image of a square external housing of an SSL assemblyaccording to the present disclosure, and illustrating an SSL lightengine;

FIG. 8 is an image of an inner surface of the square external housing ofFIG. 7;

FIG. 9 is a top plan view of a round SSL assembly according to thepresent disclosure;

FIG. 10 is a side view of the round SSL assembly of FIG. 9;

FIG. 11 is a top plan view of a square SSL assembly according to thepresent disclosure;

FIG. 12 is a side section view of the square SSL assembly of FIG. 11;

FIG. 13 illustrates exemplary components of an SSL light engine of anSSL assembly according to the present disclosure;

FIG. 14 is a parts list for the SSL light engine of FIG. 13;

FIG. 15 is an image of an outer surface of a round external housing ofan SSL assembly according to the present disclosure, and illustrating adiffusing lens positioned over an SSL light engine;

FIG. 16 is an image of an inner surface of the round external housing ofFIG. 15;

FIG. 17 is an image of an outer surface of the round external housing ofan SSL assembly of FIG. 15, illustrating the diffusing lens removed fromthe SSL light engine to reveal SSL elements mounted to a light engineboard; and

FIG. 18 is an image of the diffusing lens of FIG. 15.

DETAILED DESCRIPTION

The following description and drawings are illustrative and are not tobe construed as limiting. Numerous specific details are described toprovide a thorough understanding of the disclosure. However, in certaininstances, well known or conventional details are not described in orderto avoid obscuring the description.

Reference in this specification to “one embodiment,” “an embodiment” orthe like means that a particular feature, structure, characteristic,advantage or benefit described in connection with the embodiment may beincluded in at least one embodiment of the disclosure, but may not beexhibited by other embodiments. The appearances of the phrase “in oneembodiment” in various places in the specification are not necessarilyall referring to the same embodiment, nor are separate or alternativeembodiments mutually exclusive of other embodiments. Similarly, variousrequirements are described which may be requirements for someembodiments but not for other embodiments. The specification anddrawings are to be regarded in an illustrative sense rather than arestrictive sense. Various modifications may be made thereto withoutdeparting from the spirit and scope as set forth in the claims.

The present disclosure provides a solid state lighting fixture (SSLfixture) that can be used in outdoor and indoor recessed lightingapplications. The SSL fixture utilizes high powered solid state elements(SSL elements), e.g., LEDs, for precise efficient optical control. TheSSL fixture can be used, for example, to replace up to 175W and 250 WattHID lamps with 55 watts, and at the same time reduce maintenance bydelivery of over 200,000 hours of projected life for the SSL elements.The present disclosure also provides SSL assemblies that have an SSLlight engine and a housing capable of dissipating heat generated by theSSL light engine.

Referring to FIGS. 1-6, an exemplary embodiment of an SSL fixtureaccording to the present disclosure is provided. In this embodiment, theSSL fixture 10 includes a recessed driver housing 20 and an SSL assembly50. The recessed driver housing 20 is configured to be mounted within arecess in, for example, a ceiling or other similar structure, andsupports electrical wiring connections and one or more solid statelighting driver (SSL driver). In the embodiment shown, the interior ofthe driver housing 20 is partitioned into a driver compartment and ajunction box. The junction box is partitioned into two compartments, onefor AC wiring and the other for low voltage (e.g., dimming) wiring witha releasably secured cover, e.g., a cover that is screwed onto orsnapped onto the housing, for easy access to the compartments. Thehousing 20 also includes a pair of mounting arms 22 configured to permitsecuring the SSL assembly 50 to the recessed housing 20. An externalhousing 52 is secured to the recessed housing 20 using, for example,screws 58 secured to mounting arms 22 on recessed housing 20. Note thatthe term “screw,” as used herein, may designate any threaded component,including screws and bolts.

Referring to FIG. 5, there is shown an exploded perspective view of theSSL fixture 10 of FIG. 1, with parts of the SSL fixture shown separated.The SSL fixture 10 includes a recessed driver housing 20 and an SSLassembly 50. The following components are shown:

-   Bezel assembly 501—also shown in FIG. 13;-   Heat sink 502—supports & provides heat sinking to LED engine;-   Alternative heat sink 503—supports & provides heat sinking to LED    engine;-   Recessed housing, upper component 504—encloses electrical components    & wiring;-   Recessed housing, lower component 505—Completes enclosure of wiring    compartments, and facilitates mounting of fixture to building    components (typically conduit passing under the flanges at the front    and back ends);-   Back cover 506—completes enclosure of wiring compartments & provides    conduit fitting knockouts;-   Partition 507—completes enclosure of wiring compartments & aids in    support of driver tray 509;-   Partition 508—separates high voltage and low voltage wiring    compartments;-   Driver tray 509—supports and encloses drivers 511 and other    electrical components;-   Cover 510—encloses & provides access to wiring compartments;-   Driver 511—converts input power, typically AC, to constant current    DC suitable for powering the LEDs;-   Screw 512—secures heat sink #502 or #503 to recessed housing section    #505, with ceiling panel interposing (e.g., heat sink is pulled    against building ceiling panel);-   Cage nut 513—inserted into recessed housing section #504 for    engagement of screw #512 (e.g., to secure heat sink against    ceiling);-   Screw 514—secures back cover #506;-   Screw 515—secures driver;-   Screw 516—secures bezel assembly 501 to heat sink;-   Surge protection device 517—clamps electrical line surges above a    threshold voltage to protect drivers and other downstream equipment;-   Ground screw 518;-   Cable tie 519—for securing surge suppressor;-   Back cover component 520;-   Strain relief 521—for protection of output wires;-   Output wiring harness (partial) 522;-   Connector 523—engages the LED engine for power and dimming control    interface;-   Output wiring harness 524;-   Rubber plug 525—for aesthetic concealment of screws 512;-   Grounding lead 526.

Referring to FIGS. 7-18, the SSL assembly 50 includes the externalhousing 52, and an SSL light engine 54. The SSL assembly can co-existwith 0-10V current-sinking control devices, e.g., occupancy sensors,external dimmers, etc. The external housing 52 may come in any shape,but is shown in FIGS. 7-18 as round and square in shape. The externalhousing 52 is preferably made of a material capable of dissipating heatgenerated by the SSL light engine 54, such as cast aluminum, which willbe described in more detail below. The SSL light engine 54 is securedwithin a recess in the external housing 52, as seen in FIG. 7.

The SSL light engine 54 may be any solid state light engine, such as anLED light engine. The LED light engine may be, for example, a 24-LEDlight engine that can be field adjusted to four wattages (55, 45, 30, 15watts) and four lumen outputs. The LED light engine can come with 70 CRIin 5000 k temperature. With a 0-10 V voltage supply provided from theone or more SSL drivers, the LED light engine includes a 0-10 V dimmingcapability, with some flicker-free dimming. The luminaire efficiencyrating (LER) of the LED light engine 54 is preferably a minimum of 95,and the luminaire BUG rating preferably does not exceed B3-U1-G1.Generally, the SSL light engine 54 is preferably an optical one piececartridge system. In one embodiment, seen in FIGS. 7-14, the SSL lightengine 54 may include a light engine board 60 having one or more SSLlight elements 62, one or more lenses 68, gasket 70, and bezel board 74.In this exemplary embodiment, the light engine board 60 has one or moreSSL light elements 62, e.g., LED lamps, which can be mounted to thelight engine board 60 in different patterns. The light engine board 60is connected to one or more SSL drivers 64, e.g., LED drivers,positioned within the recessed housing 20, via cable 66 connected toconnector 67 on light engine board 60. It is noted that the LED drivercan accept 100V through 277V, 50 Hz to 60 Hz (UNIV), and the powerfactor is preferably a min 0.90 at full load. The plurality of lenses 68are positioned over the SSL light elements 62, where one lens 68 ispositioned over one SSL light element 62. Lenses 68 includes totalinternal reflection (TIR) optics. The gasket 70 has a plurality ofapertures 72 configured to align with the lenses 68, and is positionedover the light engine board 60. The bezel board 74 has apertures 76configured to align with apertures 72 in gasket 70. To secure thecomponents of this embodiment of the SSL light engine 54 together, thebezel board is positioned over the gasket 70 and secured to the lightengine board 60 as shown in FIG. 13. Each lens 68 has a plurality ofintegrated alignment pins projecting from its bottom surface. Eachalignment pin engages a hole or aperture in the light engine board 60 inorder to fix the optic location relative to the LED. This alignmentdefines the directionality of the optical distribution on the surfacebeing illuminated. In some embodiments, the alignment pins arepositioned in a regular spacing which allows the lens to be rotated indiscrete increments, for example in 90 degree increments. This rotationof the lens can be useful for producing custom distributions or opticalorientations at the customer's request. In general, each lens type is tobe positioned in a specific orientation, with text, symbols, or otheridentifying features molded or integrated into the lens 68 to define theorientation. Referring to the inset view of FIG. 13, multipleorientations of lens 68 (with respect to light engine board 60) areshown which apply to different optic types.

If the SSL light engine 54 is an LED light engine, the one piececartridge system would include a light engine board 60, one or more LEDlamps 62, optics or lenses 68, gasket 70 and bezel 74, which may be astainless steel bezel. The cartridge system is held together withinternal brass standoffs soldered to the light engine board 60 so thatit can be field replaced as a one piece optical system. A die cut foamsilicone gasket 70 ensures a weather-proof seal around each individualLED. The cartridge assembly is available in various lightingdistributions using optics, such as TIR designed acrylic optical lenses,over each LED lamp.

FIG. 13 illustrates exemplary components of an SSL light engine 54 of anSSL assembly 50, according to the present disclosure. The followingcomponents are shown:

-   Screw 1301—for retention of bezel to PCB (does not secure PCB to    housing, but retains bezel to PCB as an assembly prior to    installation);-   Washer 1302—for compression of foam bushing #1303;-   Foam bushing 1303—is compressed to apply pressure to bezel for    retention of optics within their alignment holes;-   Main gasket 1304—seals around optics;-   Perimeter gasket 1305—seals between bezel & housing, in conjunction    with main gasket;-   SSL light engine board 1306—contains LED lamps and supporting    circuitry;-   Optics 1307—refract light to create desired distribution on    illuminated surface;-   Bezel 1308—retains optics and encloses SSL light engine;-   Sealing screw 1309—provides access to rotary DIP switch for dimming    adjustment, seals aperture when in position.

In another embodiment of the SSL light engine 54, seen in FIGS. 15-18,the SSL light engine 54 may include a light engine board 60 having oneor more SSL light elements 62, and a diffusing lens 56 configured to fitwithin the recess 52 a of the external housing 52. The diffusing lens 56can be configured to provide light diffusing qualities such that aninterior surface of the diffusing lens 56 can be covered with sphericalprojections to diffuse light emitted by the SSL light elements 62.Preferably, the diffusing lens 56 is made out of a diffusing grade ofacrylic. The diffusing lens 56 may have a gasket around its perimeter,and is secured to standoffs on the light engine board 60 (e.g., the PCB)in such a way as to prevent excessive stress on the diffusing lens 56.

As noted above, the external housing 52 is made of a material that canprovide direct heat exchange between the SSL light engine 54 positionedwithin the external housing 52 and cooler ambient air. A cast aluminumexternal housing 52 provides such a direct-heat exchange between the SSLlight engine 54 and cooler ambient air. More specifically, the SSL lightengine 54 is positioned within recess 52 a in external housing 52 suchthat the surface area of the recess 52 a absorbs heat generated by theSSL light engine 54. The heat absorbed by the recess 52 a in theexternal housing 52 is then transferred to the outer surface 52 b of theexternal surface 52 so that cooler ambient air can dissipate the heat.In addition, the dimensions of the external housing 52 are such that theSSL light engine 54 is positioned outside the recess, and in instanceswhen there is a space between the SSL assembly 50 and the housing 20 anyair flow through such space can dissipate heat on the inner surface 52 cand screw bosses 57 of the external housing 52.

A thermal regulation circuit can be provided to protect the SSL fixturefrom excessive temperature by interfacing with the SSL fixture's 0-10Vdimmable drivers to reduce drive current as necessary to reducetemperature. The thermal regulation circuit activates at a specific,e.g., a factory-preset temperature, and progressively reduces power overa finite temperature range in recognition of the effect of reducedcurrent on the internal temperature and longevity of the LEDs and othercomponents. The thermal regulation circuit can directly measure thetemperature as close to the LED solder point as possible. The thermalregulation circuit can consist of surface mounted components mounted onthe light engine board 60 (e.g., printed circuit board). The thermalregulation circuit is preferably designed to “fail on”, allowing the SSLfixture to revert to full power in the event of an interruption of itspower supply, or faulty wiring connection to the drivers.

An on-board surge protector having a surge current rating of, forexample, 20,000 amps using the industry standard 8/20 pSec wave may beprovided with the SSL fixture. The surge protector can have a clampingvoltage of, for example, 825V, and a surge rating of, for example 540 J.

The foregoing specification provides a description with reference tospecific exemplary embodiments. The specification and drawings are to beregarded in an illustrative sense rather than a restrictive sense.Various modifications may be made thereto without departing from thespirit and scope as set forth in the following claims.

What is claimed is:
 1. An SSL fixture comprising: a recessed housingconfigured to be installed in a recess; and an SSL assembly capable ofbeing secured to the recessed housing outside the recess, the SSLassembly being at least partially made of a heat dissipating materialcapable transferring heat generated by the SSL assembly to ambient air.2. The SSL fixture of claim 1, wherein the SSL assembly comprises: anexternal housing; and an SSL light engine secured within a recess withinthe external housing and having one or more SSL light elements mountedto a light engine board, wherein the external housing is made of theheat dissipating material capable transferring heat generated by the SSLlight engine to ambient air.
 3. The SSL fixture of claim 2, wherein theSSL assembly further comprises a cover positioned over the SSL lightengine and secured to the external housing.
 4. The SSL fixture of claim2, wherein the heat dissipating material comprises cast aluminum.
 5. TheSSL fixture of claim 1, wherein the recessed housing comprises: a drivercompartment including dimmable drivers; and a junction box, the junctionbox being partitioned into a first compartment for alternating current(AC) wiring and a second compartment for low voltage wiring electricallycoupled to the dimmable drivers.
 6. The SSL fixture of claim 1, furthercomprising: dimmable drivers; and a thermal regulation circuitelectrically coupled to the dimmable drivers, the thermal regulationcircuit causing the dimmable drivers to reduce wattage used by an SSLlight engine in response to a detected increase in temperature of theSSL light engine above a predefined threshold temperature.
 7. The SSLfixture of claim 1, wherein the recessed housing is secured to the SSLassembly with at least two screws.
 8. The SSL fixture of claim 2,further comprising: a lens secured on a distal side of the light enginewith regard to recessed housing.
 9. The SSL fixture of claim 8, whereinthe lens is a diffusing lens.
 10. An SSL assembly comprising: anexternal housing; and an SSL light engine secured within a recess withinthe external housing and having one or more SSL light elements mountedto a light engine board; wherein the external housing is made of a heatdissipating material capable transferring heat generated by the SSLlight engine to ambient air.
 11. The SSL assembly of claim 10, furthercomprising: a cover positioned over the SSL light engine and secured tothe external housing.
 12. The SSL assembly of claim 10, wherein the heatdissipating material comprises cast aluminum.
 13. The SSL assembly ofclaim 10, further comprising: at least two screws to secure the SSLassembly to a recessed housing configured to be installed in a recess.14. The SSL assembly of claim 13, further comprising: a lens positionedon a distal side of the SSL light engine with regard to the recessedhousing.
 15. The SSL assembly of claim 14, wherein the lens is adiffusing lens.
 16. The SSL fixture of claim 10, wherein the SSL lightengine is adaptable to operate at a plurality of different wattages. 17.An SSL fixture comprising: a recessed housing configured to be installedin a recess; and an SSL assembly having an SSL light engine with one ormore SSL light elements, the SSL assembly capable of being secured tothe recessed housing outside the recess; dimmable drivers electricallycoupled to the SSL light elements; and a thermal regulation circuitelectrically coupled to the dimmable drivers, the thermal regulationcircuit causing the dimmable drivers to reduce wattage used by the SSLlight engine in response to a detected increase in temperature of theSSL light engine above at least one predefined threshold temperature.18. The SSL fixture of claim 17, wherein the thermal regulation circuitcauses the dimmable drivers to reduce wattage used by a SSL light enginein an inversely proportional response to a detected increase intemperature of the SSL light engine above a predefined thresholdtemperature.
 19. The SSL fixture of claim 17, wherein the recessedhousing is secured to the SSL assembly with at least two screws.
 20. TheSSL fixture of claim 17, further comprising: a diffusing lens positionedon a distal side of the SSL assembly with regard to the recessedhousing.